Quote:
Originally posted by mw
i believe all this histeria about a big big bore kit is rider perception not fact ...
the 620 big bore kit gives only v v slight power increase but it does give a wider power band and slightly more torque ... all to keep it on a par with a v well set up big bore 583 (it is not just about fitting a big bore kit and instantly getting the power to be on a par with the 620's you have got to sort the carburation (shorter inlets and flat slide carbs) and set it all up correctly ).
the rules were formulated to allow people 2 choices either don't fiddle and fettle and buy a 620 or buy a 583 and work to get it on a par ... infact the feeling is that the big bore 583 with correct carbs and set up would beat a 620 on power and torque ... hence having the big bore 620 option is important as this would (if you wanted to spend the money) allow one to get even ... it's all v close thou' so the extra expence probably wouldn't be worth it unless running v close to winning the championship ...
the expected power outputs of a sorted big bore 583, standard 620 and big bore 620 are all around 62 -65 bhp however all this about different dyno figures is also very misleading as each dyno has a different reading to the other ... they are useful in evaluating dif engines run on the same dyno as a comparison but not worth it between dif dynos.
also look at sigma's article on the desmo due rules to see the background.
i was overtaken by geoff at the old hairpin near the end of the 2nd race and i was overtaken by the dls/dlc bikes at barn ... eg all within a short distance. geoff has a lot of local knowledge which i suspect the others haven't ... in qualification he was 0.6 secs a lap faster, at end of race 1 he was 7.12 secs clear (about 0.6 a lap faster) and at the end of the 2nd race he was only 3.35 secs clear which means a less than 0.3 sec a lap advantage ...i don't believe that's a power advantage .. that's local knowledge ... and what everyone seems to have forgotten ... rider ability (he is a v good rider who used to race against the baines's and beat them!) it all seems to me a great shame that everyone is concentrating on the hardwear issues and taking away from geoff what was a well earned and deserved win in both races.
for what it is worth i believe changing the rules so quickly as a knee jerk reaction would be wrong ... it's just too soon ... we need to see how it goes at the next race at the v least before looking at any changes...
riders also need to look at their riding and not their machines for the fact that they were slower than the bike infront ... alan johnson on a 583 came 5th and 6th. |
I have to agree with most of what Michael has said(there has to be a first time for everything mate
) Both Neil and John Hackett, engine builders who KNOW about Ducati's have stated that a big bored 583 when set up properly with short manifolds and flat slides will MORE than live with a 620. In fact John's reasoning behind his initial development of a the '620' big bore kit was because he felt the 675's would have an advantage! Having watched all of the racing at the weekend I have to say that Geof Spencer was VERY smooth and fast everywhere I could see him, noticeably faster than most into and over the mountain-which is just race and track experience. Don't forget that Dave Riley riding a standard-eg not specially dynoed and set up-620 monster with only 1 disk- was leading race 2 for the first 2 laps-and he is a novice rider, and Andrew Johnson finished 5th on a 583!
John
[Edited on 3-5-2005 by Monty]